I have an Electrifly BLT R/C training plane that has an APC 10x4.7 plastic propeller. Using the same machining technology that I used on the turbofan I made the propeller as shown in the photo. The APC propeller produces 4oz of static thrust at 3000rpm. The Roberts propeller produces 6oz at the same rpm. The propeller is cut from ash wood and is coated with cyanoacrylate for strength. I tested the propeller at 6000rpm and got a thrust of 24oz. The blade airfoil is a NACA 6713 and has the proper helix based on the 4.7 pitch from tip to root. The trailing edge is slightly shaped for style. The propeller is mounted in pusher mode and rotates CW as seen. The root form has been increased in thickness for additional strength.
20x6 TRUFOIL TURBINAIR Propeller
The 20dia x 6in pitch TRUFOIL propeller is made with a NACA6713 airfoil from tip to root with the proper helix angle at all diameters. The root form at the hub has been thickened for strength. Made from ash wood and coated with cyanoacrylate. This propeller has been tested against a commercial 22 in dia x 8 in pitch. 22 x 8 at 6200 rpm produced 16 lb of thrust. 20 x 6 Trufoil propeller produced 16 lb of thrust at 5700 rpm.